German scientists have found that pigeons are able to switch between tasks with the same speed as humans – and sometimes even faster, writes N+1 with reference to Cell Biology.
Studies in recent years have revealed that some birds are able to handle complex cognitive tasks better than the primates. While birds have no neocortex – the region of the cerebral cortex that are associated with higher nervous functions: sensory perception, the implementation of motor commands, conscious thought and speech in humans. Birds have more neurons in the brain than might be expected at his volume, but the absolute number of nerve cells it is still inferior to the number of cortical neurons in primates.
The authors of the new work suggested that the ability of birds can be explained by a higher speed of information transmission between neighboring neurons. According to scientists, this leads to more rapid switching between adjacent areas of the brain that are used for assignments. To test this hypothesis, the researchers conducted an experiment involving 15 people and 12 rock pigeons (Columba livia).
People and birds were assigned different tasks using the same cognitive processes from participants was required to quickly switch between tasks after the beep.
People showed a column of four empty circles, divided by lines. When one of the circles lit up with white light, the person had to use the button to specify whether the circle is above or below the middle of the column. While from time to time suddenly sounded the signal “stop” and a volunteer had to switch to acoustic tasks. He was given to listen to the signal high, medium or low frequency – each sound corresponded to the top, middle or bottom line between the circles. Then the person is asked to determine the location marked by the white light of the circle relative to a new landmark.
The pigeons, in turn, were placed in the Skinner box — it is a box with artificial lighting, incentives and trough. After a preliminary education birds participated in an adapted version of the experiment. On the wall of the box there are three light indicators: one on the left and two on the right. First light up the left indicator, and if the pigeon pecked it with sufficient force, he received the award. Then, as in the first experiment, in some cases, included the “stop” signal – lighting in the box was red and lit up one of the indicators on the right. In order to treat the bird, too, had to bite.
In both experiments, a new task after the “stop” signal started either immediately or with a delay of 300 milliseconds. It turned out that the pigeons and people switch between tasks at about the same speed when it starts without a pause. If after signaling the change of job was followed by a delay, the birds reacted faster people. On average, the pigeons spent less than 200 milliseconds to start new activities.
The researchers suggest that it may be associated with a higher rate of information transfer between parts of the coat of the brain in pigeons. This feature, in their opinion, presumably is a consequence of its small size and high density of neurons. The distance between the neurons in pigeons 1.82 times less than in humans, which likely contributes to their more rapid activation.
To avoid mistakes, the authors changed the conditions of the experiment to humans. In one case, after a “stop” signal should not sound, and visual stimulus (one of the lines lit up yellow, and the position of the white circle need to be determined relative to it), however this difference on the results of the experiment are not significantly affected. In another case, the volunteers performed the same task as the pigeons, and then the characteristic of response delay after switching tasks, they were not observed, which according to the authors, indicates the inclusion of other cognitive processes.